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DISHWASHER FAULTS

Dishwasher Making Noise

Grinding, rattling, humming and knocking can come from trapped debris, spray arms hitting dishes, worn pumps, loose fittings or poor installation.

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Switch off, unplug and close the water supply before dismantling the appliance

Dishwashers combine mains electricity, hot water and hidden pumps. Stop using the machine if it leaks, trips the electrics, smells burnt or contains sharp broken glass.

MOST LIKELY CAUSES

Start with these

Spray arm striking items Tall utensils or poor loading cause repeated knocking.
Debris in pump Glass and food fragments can grind or click.
Worn circulation or drain pump Bearings and impellers may become noisy.
Loose installation Cabinet panels and hoses can vibrate.
◫ Symptom variations Match the exact point in the wash cycle. ⌄
  • Knocking during wash
  • Grinding during drain
  • Loud hum at start
  • Rattle stops when rack is rearranged
  • Noise worsens over time
✓ Quick checks Simple checks before removing panels. ⌄
  1. Note the exact cycle stage when the fault appears.
  2. Record any error code before switching off.
  3. Check filters, spray arms, hoses and visible water connections.
  4. Confirm the appliance is level and correctly loaded.
  5. Unplug before touching filters, hoses or internal parts.
If the cause is external: correct the hose, filter, loading or supply fault and test carefully.
If electrical, pump or internal leaks are suspected: stop and call an appliance engineer.
1 Step 1 — Check loading and spray-arm clearance Switch off and unplug before removing filters, hoses or panels. ⌄

Process

Spin each arm by hand and rearrange items.

Success looks like: Knocking stops.
Escalate when: A damaged arm may need replacement.
2 Step 2 — Clean filters and sump area Switch off and unplug before removing filters, hoses or panels. ⌄

Process

Remove accessible debris carefully.

Success looks like: Grinding from loose fragments stops.
Escalate when: Sharp glass may be hidden.
3 Step 3 — Note the exact cycle stage Switch off and unplug before removing filters, hoses or panels. ⌄

Process

Identify whether noise occurs during fill, wash or drain.

Success looks like: The likely pump or valve is narrowed down.
Escalate when: Persistent mechanical noise needs service.
⌁ Common causes explained Why dishwasher faults develop. ⌄

Grinding, rattling, humming and knocking can come from trapped debris, spray arms hitting dishes, worn pumps, loose fittings or poor installation.

The stage of the cycle is the main clue. Fill faults happen at the start, circulation faults during washing, heater faults once the wash is underway, and pump faults during draining.

⌘ Advanced diagnostics Appliance-engineer checks and repair work. ⌄
  • Inspect circulation pump and bearings.
  • Check drain pump impeller.
  • Inspect diverter valve.
  • Secure hoses and cabinet mounting.
  • Run service diagnostics.
▣ Parts that may need replacing Common components linked to this fault. ⌄
  • Spray arm
  • Circulation pump
  • Drain pump
  • Diverter valve
  • Mounting hardware
! When to call an appliance engineer Conditions that should end basic troubleshooting. ⌄
  • The dishwasher trips the electrics.
  • Water leaks from inside the cabinet.
  • The circulation or drain pump is grinding or seized.
  • Internal electrical testing is required.
  • The appliance must be dismantled to reach the fault.
  • The same fault returns after basic checks.
? Frequently asked questions Common dishwasher questions. ⌄

Why is there a small amount of water below the filter?

A small amount can be normal on some models. Standing dirty water above the filter usually indicates a drainage fault.

Why are plastics still wet after the cycle?

Plastic retains less heat than glass or ceramic, so some moisture is normal even when the drying system works.

Should I keep resetting the electrics if the dishwasher trips?

No. Unplug it and arrange electrical fault testing.